title: Single trial variability within the P300 (250-500 ms) processing window in adolescents with attention deficit hyperactivity disorder.
abstract: The traditional averaging process used to derive event related potential components (ERPs) is a soundly based method of determining the underlying ERP. Averaging, however, ignores the variability due to the single-trial ERPs that constitute the traditional average ERP. This variability may reflect complementary functional information to the average measure. Our group applied a simple procedure, the response variance curve (RVC), which measures single-trial ERP variability relative to their average. In this study, the average ERP and RVC measures (generated from the same single-trial task-relevant target ERPs) were assessed in an auditory oddball paradigm, in 17 unmedicated male adolescents with attention deficit hyperactivity disorder (ADHD) and in 17 age- and sex-matched normal controls. P300 amplitude, latency and point of maximum variability of the RVC were measured within the P300 processing window (250-500 ms post-stimulus). There were no significant differences in P300 amplitude or latency between the groups. Unmedicated ADHD patients, however, showed significantly increased single-trial variability within the P300 window compared with controls. This variability was significantly reduced with stimulant medication.
authors.affiliation: Department of Psychiatry, Westmead Hospital, University of Sydney, NSW, Australia.
authors.forename: I
authors.initials: I
authors.lastname: Lazzaro
authors.forename: J
authors.initials: J
authors.lastname: Anderson
authors.forename: E
authors.initials: E
authors.lastname: Gordon
authors.forename: S
authors.initials: S
authors.lastname: Clarke
authors.forename: J
authors.initials: J
authors.lastname: Leong
authors.forename: R
authors.initials: R
authors.lastname: Meares
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology*; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D002648:Child; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D009482:Neurophysiology / Q000379:methods; D011930:Reaction Time / Q000502:physiology*
chemical_list: D000697:Central Nervous System Stimulants